Have you checked the IAC? Innercooler hoses all tight? I chased similar issues a few years ago. I can't remember if it was a bad IAC but I do remember for one of the issues, it was a simple dumb ass problem. Bottom hose on the innercooler popped off and was causing all kinds of (expected)...
Here are a few threads that may or may not help:
https://turbobuick.com/threads/200r4-trans-code-help-needed.451305/
https://turbobuick.com/threads/ktf-whats-it-out-of.179498/
https://turbobuick.com/threads/ktf-code.326480/
And the lower I/C hoses. Easy to overlook if you're just looking at everything up top. I had one pop off on my front mount years ago and chased a red herring for a bit before looking under there and seeing it dangling. DOH! comes to mind. Live and learn.
Autometer WBs aren't in the Powerlogger drop down menu but they do work with it. Here's a thread discussing one of the Autometer model #s:
https://www.turbobuick.com/threads/new-to-powerlogger-autometer-wideband-compatible.392671/
Compared to those on this forum, I know comparatively nothing about these cars but I would do a heater calibration regardless of whether it could remotely be related or not. Don't cost nothin' and not doing one on my car cost me a LOT both in terms of time and $$$ (well spent $$$ but $$$...
Frames 7768 and 10,623 you had just gotten out of it but it was still registering KR. That seems odd.
Do you have a volt booster installed or something that makes the volts increase to 16v when you're into the throttle?
As Scooby noted, your narrowband is dropping down very low and...